.main_box{
	width: 100%;
	height: 1200px;
	padding-top: 200px;
}
.main div{
	width: 80%;
	height: 260px;
	margin-left: 10%;
	margin-bottom: 10%;
	background-color: white;
	border-radius: 100px;
	margin-top: 5%;
	
}
#f1{
	background: url(../img/narrate/ziran.png);
	background-position: center 0;
	background-repeat: no-repeat;
	background-size: cover;
}
#f2{
	background: url(../img/narrate/minsu.png);
	background-position: center 0;
	background-repeat: no-repeat;
	background-size: cover;
}
#f3{
	background: url(../img/narrate/lishi.png);
	background-position: center 0;
	background-repeat: no-repeat;
	background-size: cover;
}